John flammangr



J. FLAMMANG.

PISTON.

APPHCATION FILED MAY 2a, 1918.

1,336,690; Patented Apr. 13, 1920.

UNITED STATEJQFATENT OFFICE.

JOHN FLAMMANG, OF ST. LOUIS, MISSOURI, ASSIGNOR T0 OTTMAR G. STARK, OF ST.

I LOUIS, MISSOURI.

PISTON.

To all to 7mm it may concern:

Be it known that I JOHN F LAMMANG, a citizen of the United states, residing atthe city of St. Louis and State of Missouri, have invented a new and useful Piston, of which the following is a specification.

This invention relates to pistons.

The object of the invention is to provide a piston including a lower portion and an expansible and compressible upper portion of novel construction arranged to expand by the resiliency of the metal, and provided with a novel form of joint between the sections thereof to prevent the passage of gas, steam or other operating agent.

Other objects will appear from the following description in which reference is made to the accompanying drawings illustrating a preferred form of the invention, in which Figure 1 is. a view partly in section of the casting from which the piston is constructed.

Figs. 2 and 3 are views illustrating the casting after the upper portion thereof has been divided into segmental sections and the holes for the wrist pin formed in the casting. V

Fig. 4 is an elevation of the casting after it has been subjected to an additional treatment to close the openings formed by the cutting of the upperportion of the casting into segmental sections.

Fig. 5 is a view ofthe casting after the upper portion thereof has been finished as to its circumferential surface.

Fig. 6 is a view partly in section after the wrist pin has been placed in the casting and the casting has been finished.

Fig. 7 is a view showing the piston body after the same has been finished.

Fig. 8 is a View of the finished piston having the top orhead plate in connection therewith.

Fig. 9 is a view of the piston within a cylinder.-.

The casting from which the piston body is manufactured includes a lower ring 1 an upper ring2, connections 3 integrally uniting the lower and upper rings, and

bosses 4 extending inwardly from the connections 3, said bosses constituting supports for the wrist pin. The casting thus con- Specification of Letters Patent. Patented A1313 13 1920 Application filed May 23, 1918.

Serial No. 236,191.

structed is treated to make the upper ring 2 expansible and compressible so that when placed within a cylinder the upper portion of the piston will impart pressure a ainst the wall of the cylinder all around an thus dispense with the necessity of using piston rings or packing in connection with the piston. For this purpose the connections 3 are cut inwardly from their opposite side edges as shown at 5. The cuts 5 extend preferably somewhat less than half the width of the connections 3, and each of the cuts 5 is intersected by a cut 6 extending to the upper edge of the ring 2, thus dividing the upper portion of the casting into segmental sections which are independently supported by the connections 3 respectively. As shown, the cuts 6 are oblique or inclined relative to the axis of the piston body and this is the preferred construction, though it is apparent that the cuts 6 may be otherwise formed if desired. The cuts 6 are also preferably inclined relative to the radii of the casting so that the inner portion of each segmental section engages or extends under the adjacent segmental portion.

Holes 7 are formed through the connections 3 and the bosses A for receiving the wrist pin of the piston. As shown the holes 7 are inclined inwardly and downwardly, so that when the wrist pin 8 is placed therein the connections 3 will be forced apart and placed under tension.

After the upper portion of the piston body has been divided into segmental sections the sections are treated in order to cause the ends of the segmental sections to close the openings or cuts 5. The treatment consists in pressing the ends of the segmental sections into contact with the connections 3 from which the ends are separated by the cuts 5 and subjecting the piston to treatment to cause the segmental sections to desired. The depression of the ends of the segmental sections of the upper ring of the piston body places them approximately 1n the position shown in Fig. l, and thereafter the upper end of the piston body is ground or finished to provide a properly smooth surface upon which the head or top plate of the piston is to be mounted.

The head or top plate of the piston is illustrated in Figs. 8 and 9 and comprises a disk 9 having an annular flange 10 extending into the upper portion of the piston. The flange 10 may also be formed with a circumferential flange 11 which will engage in a groove formed inside the upper ring of the piston body thus forming an interlocking connection between the top or head plate of the piston and the piston body. Also, if de sired, keys 12 in the form of thin plates may be seated in the slots in the upper portion of the piston body and engaged within notches or recesses in the flange 10 of the top plate.

The diameter of the head or top plate 9 is approximately that of the cylinder for which the piston is intended while the diameter of the upper portion of the piston body comprising the segmental sections of the ring 2 is held under tension to a diameter slightly in excess of that of the cylinder for which the piston is intended. The diameter of the lower portion of the piston body is slightly less than the diameter of the cylinder in which the piston is to be used and, when the piston is placed within the cylinder, the expanded upper portion of the piston is compressed so that a close fit is formed. Thus, the resiliency of the metal is utilized to press the upper portion of the piston against the cylinder wall throughout the circumference of the piston, and since the extremities of the segmental sections of the ring 2 are overlapped at or near the radial lines along which the expansion is effected by the resiliency of the connections 3, it is clear that pressure is imparted against the cylinder wall throughout the entire circumference of the piston and that this pressure is approximately uniform at all points.

My improved piston therefore dispenses entirely with the need of piston rings or packing of any character and the resiliency of the material of the piston is utilized to impart pressure uniformly against the cylinder wall at all points throughout the circumference of the piston.

The piston thus constructed is simple and easily applied, and being provided with a removable top or head plate can be readily repaired in case any of the parts become broken or damaged.

What I claim and desire to secure by Letters Patent, is

l. A piston composed of a hollow body whose upper portion is divided into segmental sections having overlapping ends, said upper portion being of larger diameter than the diameter of the lower portion of the body.

2. A piston composed of a hollow body whose upper portion is of larger diameter than the lower portion, and said upper portion being divided into segmental sections having overlapping ends which are held under tension whereby the resiliency of the metal will press the segmental sections against the wall of the cylinder in which the piston is mounted.

3. A piston comprising a hollow body whose upper portion is divided into segmental sections having overlapping ends, said upper portion being of a diameter in excess of the diameter of the lower portion of the body and of the diameter of the cylinder for which the piston is intended, and being compressible into the cylinder, whereby when the piston is placed in the cylinder the segmental sections of the upper portion of the piston will be pressed against the cylinder wall by the resiliency of the metal.

a. A piston comprising a body composed of a lower ring, an upper ring divided, into segmental sections having its ends overlapping and being of a diameter in excess of the diameter of the cylinder for which the piston is intended, and connections integrally uniting the segmental sections of the upper ring with the lower ring.

5. A. piston comprising a body composed of a lower ring, an upper ring divided into segmental sections having its ends overlapping and being of a diameter in excess of the diameter of the cylinder for which the piston is intended, connections integrally uniting the segmental sections of the upper ring with the lower ring, and a top plate in connection with the upper ring.

6. A. piston comprising a body composed of a lower ring, an upper ring divided into segmental sections having its ends overlapping and being of a diameter in excess of the diameter of the cylinder for which the piston is intended, connections integrally uniting the segmental sections of the upper ring with the lower ring, a top plate mounted on the upper ring, and means removably holding the top plate in connection with the upper ring of the piston.

7. A piston comprising a body composed of a lower ring, a number of segmental sections forming an upper ring, and connections integrally uniting the segmental sec tions of the upper ring with the lower ring, the free ends of the segmental sections bearing upon adjacent connections.

8. A piston comprisinga body composed of a lower ring, a number of segmental sections forming an upper ring, connections-integrally uniting the segmental sections of the upper ring with the lower ring, the free ends of the segmental sections bearing upon adjacent connections, and a wrist pin secured to said connections.

9. A piston comprising a body composed of a lower ring, a number of segmental sections forming an upper ring, connections integrally uniting the segmental sections of the upper ring with the lower ring, the free ends of the segmental sections loearin upon adjacent connections, a wrist pin secured to said connections, and a top plate connected to the upper ring.

10. A piston comprising a body composed of a lower ring, a number of segmental sections forming an upper ring, and connections integrally uniting each of said sections with the lower ring and constituting a support for the free end of the adjacent section, and a top plate in connection with the upper ring.

' JOHN FLAMMANG. 

